1. Field of the Invention
This invention relates to open power boats of the type used in fishing and other recreational boating and, more particularly, to the hull configuration thereof.
2. General Background
In smaller vee entry boats rated for one hundred (100) h.p. but yet having top speeds in excess of fifty (50) mph, with which the invention is particularly concerned, the choice of hull configuration has conventionally involved various tradeoffs among the more desirable criteria, which includes safety and fuel economy on the one hand and high speed performance on the other. These tradeoffs are nowhere more evident in a conventional vee planing hull than in a sharp course correction from "full out" on plane running where, from the standpoint of safety, it is necessary to come substantially offspeed to achieve the increased wet planing area necessary for turn tracking stability. This, of course, produces a significant increase in drag with a concomitant decrease in fuel efficiency, both in the turning maneuver and bringing the boat back to full plane after the course correction. It is the purpose of this invention to resolve these conventional tradeoffs as related to high speed course correction.
High speed turns are one of the more dangerous boating maneuvers that are particularly unforgiving of the novice boater who has not mastered the feel for coordinating trim and throttle adjustments at the inception and execution of the turn. Indeed, it is a rare expert who, even when throttling back from top speed and entering a proper trim adjustment, has not felt unanticipated stern slippage or "chine walk".
The prudent boater thus comes drastically offspeed to execute a sharp turn. The decrease in speed, of course, results in a greater wetted area of the hull, puts more chines in the water, and most importantly, reduces the magnitude or arc of the layover angle which the outer running surface of the hull on the inside of the turn makes with the water surface. The consequence of the latter is that with the lesser arc of downward movement in a given time frame, the laying over of the outer running surface into wetting contact does not produce the violent slapping and bouncing from the surface that initiates repeated slapping impacts and violent stern slippage that is characteristic of a high speed turn under full throttle where the arc of descent is substantially greater from the full on-plane position.
The foregoing is a typical performance of conventional vee hulls having the usual planar running surfaces, separated by chines, on either side of the keel line running surface which lateral, planar running surfaces and the central keel line running surface, when viewed in transverse section adjacent the aft end of the boat, exhibits a typical V-shape terminating laterally at outer chines continuous with the sides of the boat.
As related to the present invention, it is important to note that prior art hulls of the type herein comtemplated have employed planar outboard running surfaces to more easily "slip" the water and avoid low speed cavitation.
A typical high performance type hull configuration is shown in U.S. Pat. No. 4,465,009, where high speed turning characteristics are increased by the use of after, outboard running surfaces which are concavely configured.
Another typical hull configuration, such as shown in U.S. Pat. No. 3,216,389, where all the running surfaces are concave, is distinguishable in kind from high performance type hulls such as described in U.S. Pat. No. 4,465,009 since inherent hull cavitation over the entire speed range of such a boat is inconsistent with the purposes therein, which is directed to performance parameters in that speed range beyond the reach of such atypical hulls.